Advice on what shaders to use for stylised reptile skin?
For simple procedural recreation of this material you can use Principled BSDF shader with some simple textures:



As a color I've used only Noise texture with Color Ramp to give a little variation for it. In your example texture is indeed hand painted.

The reflective part is Clearcoat and Roughness dropped to .3

Green border marks bumps created from Voronoi textures. I've used them as Normal and Clearcoat Normal.

The light rim is made by using two big Area Lamps placed behind model: